Evolution of fabric anisotropy of granular soils: x-ray tomography measurements and theoretical modelling
Evolution of fabric anisotropy of granular soils: x-ray tomography measurements and theoretical modelling
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DOI：
10.1016/j.compgeo.2021.104046
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发表时间：
2021-05
影响因子：
5.3
通讯作者：
Chaofa Zhao;G. Pinzón;Max Wiebicke;E. Andò;N. Kruyt;G. Viggiani
中科院分区：
文献类型：
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作者：
Chaofa Zhao;G. Pinzón;Max Wiebicke;E. Andò;N. Kruyt;G. Viggiani
组构各向异性是理解粒状土特性的关键组成部分。一般来说，真实的粒状土的组构各向异性的实验数据非常有限，特别是在临界状态下。本文利用X射线层析成像技术对两种颗粒土剪切带内的接触组构各向异性进行了实验研究。然后，这些数据被用来评估各向异性临界状态理论（ACST）的有效性和准确性的织物演变规律，以前开发的DEM模拟的结果理想化的材料。总的来说，实验结果支持ACST，根据其独特的（即，与初始条件无关）在大应变下观察到组构各向异性和配位数的值。随着材料圆度的增加，接近临界状态的速率增加。实验测得的组构各向异性的演变是相当好的再现所提出的演变规律。
Fabric anisotropy is a key component to understand the behaviour of granular soils. In general, experimental data on fabric anisotropy for real granular soils are very limited, especially in the critical state. In this paper, x-ray tomography measurements are used to provide experimental data on contact fabric anisotropy inside shear bands for two granular soils. The data are then used to assess the validity of Anisotropic Critical State Theory (ACST) and the accuracy of a fabric evolution law that was previously developed from the results of DEM simulations on idealised materials. Overall, the experimental results support ACST according to which unique (i.e., independent of initial conditions) values for fabric anisotropy and coordination number are observed at large strains. With increasing roundness of the material, the rate at which the critical state is approached increases. The evolution of fabric anisotropy measured from the experiments is fairly well reproduced by the proposed evolution law.